Publicado 12 números por año
ISSN Imprimir: 0040-2508
ISSN En Línea: 1943-6009
Indexed in
Q-FACTOR MEASUREMENTS UNDER CONDITIONS OF CLOSELY-SPACED RESONANT FREQUENCIES OF MODES IN OPEN RESONATORS
SINOPSIS
A method is suggested for measuring Q-factors of microwave resonators. The technique enables investigating properties of materials and media using open resonators of various types in the presence of modes with closely-separated frequencies in the vicinity of the selected oscillation mode, radiation loss of the coupling elements and cross-talk interference between them. The measurement of the loaded Q-factor is based on representation of the frequency dependence of the complex-valued reflection or transmission factor by a sum of homographic complex-valued functions which describe responses of individual modes, and approximation of the square of the measured amplitude-frequency characteristic using the variational gradient technique. The method of estimating the intrinsic Q-factor is based on calculating the resonator impedance using the measured magnitude of the reflection factor. The developed algorithms have been implemented as a computer program and analyzed using an example of processing of frequency dependences of the S-parameters of a mirror dielectric open resonator supporting the whispering-gallery modes. At that the S-parameters have been calculated by the finite-element method. The technique suggested for measuring the Q-factors is free of the systematic measurement error associated with distortions of the resonance curves and makes it possible to perform measurement under conditions when the classical methods break fail.
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Breslavets A. A., Eremenko Z. E., Rudnev G. O., Natarov M. P., Glamazdin V. V., Shubnyi O. I., Voitovych O. A., Gang Zhu, Rong Li, Prokopenko A. A., Hemispherical X band microwave small sized open resonator for wide range from 1 to 20 permittivity characterization of solid-state dielectrics, Low Temperature Physics, 48, 1, 2022. Crossref